Introduction Mastitis is the inflammation of the mammary gland caused by invading pathogens. Many candidate genes for mastitis tolerance are being studied in a variety of populations so as to find out the molec- ular markers. Majority of these candidate genes have one or multiple roles in the host immune sys- tem. Genes associated with immune responses of mammary gland are potential genetic markers be- cause of their importance in mastitis. Besides, genes associated with neutrophil function are po- tential genetic markers for mastitis, as neutrophil migration from blood to the sites of infection is es- sential for resolution of most mastitis pathogens (Paape et al., 2000). The ability of neutrophils to migrate into infected tissues is dependent upon recognition of inflammatory mediators by neu- trophil cytokines, chemokines, and complementary receptors (Burvenich et al., 1994). One of the important chemokine associated with leukocyte migration is interleukin-8 (IL-8), which is an ELR+ CXC chemokines, that interacts with specific chemokine receptors viz. CXCR1 and CXCR2 present on the neutrophils surfaces (La- haussa et al., 2008). These chemokines receptors are required for maximum neutrophil function dur- ing infection (Murphy and Tiffany, 1991). Recog- nition of chemokines by CXCR1 and CXCR2 induces neutrophil activation, chemotaxis and eventually phagocytosis of pathogen (Peveri et al., 1988, Podolin et al., 2002). Being receiver and transmitter of the signal from IL-8 to downstream, the receptors of IL-8 are the important candidate genes for mastitis tolerance/susceptibility study in the herd. Single Nucleotide Polymorphisms (SNPs) have been identified in the bovine CXCR1 and is found to be associated with mastitis resistance. However, CXCR2 still needs to be explored for SNPs associated with mastitis resistance. In the present paper, PCR-SSCP is proposed to identify SNPs in CXCR2 recptor gene of cattle and associ- ated it with mastitis resistance in cattle. PCR-SSCP method is easy, sensitive, effective and inexpensive *Corresponding author:Dige Mahesh Shivanand Address: Division of Animal Genetics and Breeding, Indian Veteri- nary Research Institute, Izatnagar, Bareilly (Uttar Pradesh) - 243122 India E-mail address:maheshdige@gmail.com Journal of Advanced Veterinary Research Volume 1 (2011) 52-56 PCR-SSCP and Sequencing of CXCR2 Receptor Gene in Vrindavani Cattle Dige Mahesh Shivanand 1 *, S.P.S Ahlawat 1 , Bharat Bhusan 1 , A. K. Tiwari 2 , Arvind Sonawane 1 , Push- pendra Kumar 2 , B Inamdar 1 , Triveni Dutt 3 1 Division of Animal Genetics and Breeding, Indian Veterinary Research Institute, Izatnagar, Bareilly (Uttar Pradesh) - 243122 India. 2 Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly (Uttar Pradesh) - 243122 India . 3 Division of Extension Education, Indian Veterinary Research Institute, Izatnagar, Bareilly (Uttar Pradesh) - 243122 India (Recieved 11 May 2011/ Accepted 10 Juli 2011) Abstract Genetic markers associated with inflammatory responses during mastitis could aid in the selection of diseased cattle. One potential marker is CXCR2, a chemokine receptor required for neutrophil migration to infection sites. The objective of this experiment was to identify genetic polymorphism of CXCR2 gene and associate it with subclinical and clinical mastitis. Ninety five Vrindavani crossbred cows (42-mastitis tolerant and 53-clinical mastitis) that completed at least two full lactations were taken for study. Blood of selected crossbred cows was collected, and genomic DNA was isolated by phenol chloroform method. The DNA of good quality having OD ratio (260/280 nm) between 1.7-1.9 were used for further analysis. PCR-SSCP technique was used to reveal the polymorphism in 269bp fragments of CXCR2 gene. The 269 bp fragment of CXCR2 gene was found to be monomorphic in all the DNA samples of crossbred cows. Keywords: CXCR2 Receptor gene; PCR-SSCP; Vrindavani; Cattle; Sequencing Original Research ISSN: 2090-6277/2090-6269, www.advancedvetresearch.com